1. Field of the Invention
The present invention pertains to a rotary coupler device for transmitting a light signal between two relatively rotating optical fibers or waveguides.
2. Background Art
The development of optical fibers or waveguides for the transmission of light as a signal transmitting medium has offered several advantages in the art of data and communications transmission. However, one problem associated with signal transmission through optical fibers pertains to the requirement that the discrete fiber elements must be precisely aligned with and maintained in close proximity to each other at connections therebetween to avoid signal losses at the connections. The problems associated with reducing signal losses at static connections between end to end connected optical fibers, are aggravated when it is necessary to provide for a connection wherein one fiber is required to rotate with respect to another.
The problem of transmitting electrical signals from one member to another wherein the members are rotating relative to each other, has been solved by the so called slip ring device wherein a brush contact member is resiliently biased against a rotating cylindrical ring to accomplish signal transmission between relatively rotating members. However, in the transmission of light signals between relatively rotating members, precise alignment of the members is required while maintaining the members physically in non-contacting relationship.
Prior art efforts to develop optical fiber rotary couplers have resulted in very expensive devices which are still subject to dimensional tolerance errors in positioning one optical fiber with respect to the other. Moreover, prior art devices have not been particularly adapted for use with an electrical signal rotary coupler or slip ring assembly. Since there are many applications for optical fiber signal transmission systems which are used conjointly with electrical signal transmission systems, it is particularly desirable to provide a rotary coupler which is adapted for transmission of electrical signals as well as optical signals between relatively rotating structures. In this respect, the present invention is also directed to an improved rotary coupler or an optical fiber signal transmission system which is particularly adapted to be used in conjunction with an electrical slip ring assembly.